I'll check the fluids and see if that's it. That engine code reader is probably beyond my comfort zone, but thank you for suggesting a solution.

The engine is probably either the 5.3L 318 V8 or the 5.9L 360 V8. If the levels for oil, radiator and transmission are where they are supposed to be it's unlikely that the check engine light involves fluids.

Before getting into the clutches of a repair shop that might charge $75-100 to just identify the trouble code, I suggest you purchase a very inexpensive basic OBD 2 code reader, for example:

Your coach has the receptacle to plug in a OBD2 code reader underneath the dashboard. With this reader you just plug it in, enter the make and model of the engine, let the engine run briefly and the reader will spit out the trouble code which you can google to get detailed information on what the problem is. Also with the code reader you can clear the trouble code and see if it recurs or if it was just a one shot event.

It's been a while (we now have our own reader), but it used to be that you could go to an auto parts store and leave a credit card deposit for a 24 hr code reader rental. They didn't charge for the reader (hoping you would come back to buy parts) and you got the deposit back when you returned the reader. Might be faster than ordering one.

We lived in such a small town that if you could drive to the store and they weren't busy, the guy behind the counter would come out and read it for you. (Especially if you were, as I was, old enough to be his mother).